The quality factor "Q" which characterizes the relative damping of an electromagnetic resonator operating at its resonant frequency is directly proportional to the energy stored by the resonator and inversely proportional to the average power dissipated in resistive components of the resonator. The energy stored by the resonator is in turn directly proportional to its inductance. Accordingly, in order to increase the Q of an electromagnetic resonator one may increase its inductance by increasing the number of turns in inductors incorporated in the resonator (the inductance of an inductor increases in proportion to the square of the number of turns in the inductor); or, one may decrease the resistance of the resonator. Unfortunately, if the resonator inductance is increased by increasing the number of inductor turns, there is a proportional increase of the resonator resistance, due to the addition of resistive inductor turn material. Similarly, if the resonator resistance is decreased by removing resistive inductor turn material, then there is a proportional decrease of the resonator inductance. The result is that the resonator Q can be increased only marginally by this technique.
The foregoing limitations are not of particular concern for resonators having high resonant frequencies, because the resonator Q is also directly proportional to its resonant frequency. However, at low resonant frequencies, such as the audio frequency range, the limitations aforesaid effectively preclude construction of a high Q low frequency resonator. Typically, Q is very much less than 100 for an inexpensive audio frequency resonators practical size.
Recent advances in superconductor technology which have dramatically elevated the minimum temperature at which certain materials become superconductors (i..e. the minimum temperature at which such materials have negligible resistance to the flow of electric current) facilitate the construction of low cost, high Q low frequency resonators. This is because the number of turns of a resonator inductor may be increased, without yielding a corresponding increase in the resonator resistance if the resistive components of the resonator are cooled to the minimum temperature required for those elements to operate as superconductors. Because superconductors have negligible resistance, and because the resonator Q is inversely proportional to its resistance, very high resonator Q may be attained independently of the resonator frequency. Even so it would ordinarily be necessary to separately construct the inductive and capacitive components of-the resonator with superconductor material and then connect those component together with superconductor material. The present invention greatly simplifies resonate construction by facilitating formation of the capacitive and inductive components as unitary superconductor material components.